1. Field of the Invention
The present invention relates to a semiconductor device and an assembling method thereof, and more particularly relates to a resin mold type semiconductor device and an assembling method thereof, in which a semiconductor chip, parts of leads, wires and so on are molded and encapsulated by synthetic resin.
2. Description of the Related Art
Conventionally, there is a semiconductor device disclosed in Japan Patent Application Laid-Open No. 61-218139 in 1986 or the like.
FIG. 8 is a sectional view of a conventional resin mold type semiconductor device.
As shown in FIG. 8, the resin mold type semiconductor device is provided with a semiconductor chip 1, an insulating tape 2, a lead 3, a metal plate 4, a ball 5, a wire 6 and molded resin 7.
The resin mold type semiconductor device has a LOC (Lead On Chip) structure which the lead 3 is adhered to a surface of the semiconductor chip 1 by the insulating tape 2.
As to a resin mold type semiconductor device like this, the space between a side of a package and the semiconductor chip 1 tends to become narrower as the semiconductor chip (pellet) 1 becomes larger. This is caused by the fact that the package can not made larger, because the size of the package, which stores the semiconductor chip 1, is standardized though the semiconductor chip 1 is made larger.
There is a problem in that a crack 8 may occur in the body of the semiconductor device due to the heat during substrate mounting. Since water is absorbed while the semiconductor device is kept in air and the water is vaporized by the heat during substrate mounting, the force of the vapor causes the crack 8.
Particularly, the insulating tape 2 tends to absorb water, therefore, there are many cases that the crack 8 is caused by the insulating tape 2.
The insulating tape 2 also prevents the semiconductor device from being made thinner.